EF

EF

1. (metrology) Symbol for exafarad, an SI unit of electrical capacitance equal to 10¹⁸ farads.
2. (climatology) Köppen climate classification for an ice cap climate.
3. (international standards) Indeterminately reserved ISO 3166-1 alpha-2 country code for the Union of Countries under the European Community Patent Convention.

• (ISO 3166): This is an indeterminately reserved code, included as part of ISO 3166-1 on the request of the World Intellectual Property Organization due to its former intended use in the WIPO ST.3 standard, and is not endorsed for general use by the ISO.

EF (plural EFs)

1. (medicine, cardiology) Initialism of ejection fraction.
2. (electricity) Initialism of electric field.
   • 2024 August 19, “LAKETOWN 115-kV TRANSMISSION LINE PROJECT IN CARVER COUNTY, MN”, in Great River Energy‎, pages 55, 74:

     Under certain conditions, the localized EF near an energized transmission line conductor can produce small electric discharges, ionizing nearby air. Modern “bipolar” cardiac devices are much less susceptible to interactions with EFs. Manufacturers of pacemakers and other IMDs have indicated that EFs below 6 kV/m are unlikely to cause interactions affecting the operation of most of their devices.

EF

1. (computing, Microsoft) Initialism of Entity Framework, an open-source ORM framework.
2. (Canada, US, meteorology) Followed by a number from 0 to 5: initialism of Enhanced Fujita, a rating on the Enhanced Fujita scale used to indicate the intensity of a tornado; it has superseded the Fujita scale.
3. (Roman Catholicism) Initialism of Extraordinary Form.

EF (not comparable)

1. (philately) Initialism of extremely fine or extra fine; also XF.

• F&E, FE, Fe, f.e.

• IPA^(key): /ˈeːʔɛf/

EF m (strong, genitive EFs or EF, plural (formal) EF or (colloquial) EFs)

1. (historical, military) one-year volunteer (abbreviation of Einjährig-Freiwilliger)

• The plural often takes no ending in formal standard German. In less formal speech, however, -s is only rarely omitted.

• EFschaft
• EFK